We'll get plenty of "action-hobbit" with the spiders in Mirkwood...by this time in the story is it really THAT much out of character? In the book, wasn't it told from Bilbo's POV? When he woke up the battle was pretty much over. You know that wouldn't fly in a big-budget adaptation...the ONE huge battle in the book goes unseen? I doubt PJ will have Bilbo on a white horse leading the army of men. He'll probably just slip on the ring and comically pick off orcs. Maybe he'll save a dwarf's life or something. By this point in the book it wouldn't be out of character at all.